The present invention relates to the art of construction, in particular in connection with the integration of joist and beam supports with poured concrete walls, and more particular, those concrete walls utilizing insulated concrete forms.
In the construction of buildings, residential or commercial, concrete walls are poured utilizing forms secured in place and between which the concrete is poured. Insulated concrete forms are those premanufactured forms made of sturdy spaced apart essentially planar insulating members (usually polystyrene material, commonly called styrofoam) premanufactured as a unit (in blocks, planks or panels) held together in a spaced apart fashion utilizing plastic or metal form ties. Insulated concrete forms coming in double paneled blocks, for example, are placed one on top of the other to create a double formed wall in which the concrete is poured, to create, upon curing of the concrete, not only a sturdy concrete wall, but an insulated one as well.
This method of construction presents unique problems associated with securing the next higher floor's flooring system as it connects to the top of the concrete wall. This problem exists because most insulated concrete forms are utilized with multi-story concrete walls that comprise a continuous concrete wall from story to story. Thus, some method of installing joist or beam hangars, or the like, is necessary to incorporate into the concrete wall as it is being built. However, even in those buildings utilizing concrete walls on one level only, or those utilizing stay-in-place concrete forms, an easy to use sturdy joist hanger built into the concrete wall is desirable. It should be understood that although the terms joist and beams are utilized, the invention envisioned herein addresses problems associated with supporting the ends of any elongated support member, including trusses and the like.
The existing art, such as that shown in Watkins, U.S. Pat. No. 5,228,261, utilizes a multi-part device utilizing a continuous U shaped element held in place utilizing insertable/removable horizontal rebars; moreover, it requires a fairly time consuming task of cutting a specific U shaped design into the insulation material to match as closely as possible the shape of the U shaped member. Moreover, such a hangar allows for as much as 2 to 3 inches of what is essentially open space between the concrete and the end of the joist member being supported so as to create an undesirable bending moment creating significant bending stress about the edge of the concrete wall where the device meets the concrete wall. This bending moment has both horizontal and vertical forces, the horizontal forces of which are undesirable. It also necessitates time and labor in tying such a device to the existing rebar structure of the concrete. Moreover, such a device is obtrusive in terms of concrete flow inside the wall during pouring, and consequently provides an impediment in a smooth concrete flow and further provides opportunities for concrete integrity challenging air pockets to develop on the underneath sides of the channel member inside the wall.
Ledger boards are also sometimes used in place of hangars. These ledger boards are secured to the concrete wall during construction, but do not rest on the concrete wall as is the preferred method in typical wood frame construction. Consequently, ledger boards which are not only time consuming to install and connect to the joist, provide the weak point of contact between the floor, floor joist and concrete wall, there being no floor joist resting on a concrete wall or metal hangar secured in the concrete wall. Moreover, the ledger board is subject to shifting inasmuch as construction requires a large number of holes to match up with concrete supported bolts, a difficult to achieve task that usually results in larger than necessary holes in the ledger board creating tendencies for shifting and for weakness in the board. Moreover, ledger boards allow for risks of rot and termite infestation and shrinkage in dry climates, all undesirable elements for key structural members.
The present invention provides a minimal amount of structure to interfere with the concrete flow, yet provides a self-contained rebar arrangement in the preferred form. It also allows a unique and quick attachment to the vertical rebars if desired. It also provides an easy to construct back T-bar plate to achieve the desired objectives and has means for easily attaching to the existing furring strips that are integral to the insulated concrete form to provide a method for securing and holding the device during the rigors of concrete pouring, and also, in an alternative mode, allows for maintaining the placement of the hangar during the shifting of the forms that sometimes occur during pouring.
Thus the present invention is a sturdy, single part hangar that is quick and easy to install that is designed in the preferred mode to “connect” to an existing vertical rebar, if needed, or can be utilized without the rebar at the discretion of the builder, and provides for a device having a back plate member, and further is designed so as to allow a direct contact between the back plate and the concrete structure so as to disallow bending forces on the device and so as to further minimize any horizontal forces that would pull the hangar away from the wall. It is an inexpensive, easy to construct, solid single unit hangar member that can be easily intertwined with the vertical reinforcing bar members of the concrete wall if desired, and that provides for flush contact between the vertical face of the hangar and the concrete associated with the wall.
Moreover, it provides for clean connections and abutments, easily allows for beams placed at an angle such as those adjoining the wall at a 45 degree angle and allows for full concrete flow in and around the device to minimize, and essentially eliminate, air pockets of concrete that would otherwise be caused by the presence of the device.
Additional objects and features of the invention and the manner in which the invention achieves its purpose will be appreciated from the foregoing and the following description and the accompanying drawings which exemplify the invention, it being understood that changes may be made in the specific method and apparatus disclosed herein without departing from the essentials of the invention.